Generator control



Oct. 18, 1932. D. L. WERTZ 1,883,428

GENERATOR CONTROL Filed Aug. 11, 1951 2 Sheets-Shee 1 'JasI nLtwn/ AAA/\AA HHIIIII INVE/VTOR QC. w/exvf/z A T TOR/VEY v iiiiiiiiiii2E5;

INVENTOA TTORA L. VVERTZZ site E8, 1932 GENERATOR CONTROL Filed Aug. 11, 1931. 2 Sheets-Shee Patented Oct. 18, 1932 1 UNITED STATES PATENT OFFICE DANIEL L. WERTZ, OF ELMIRA, NEW YORK, ASSIGNOR TO ECLIPSE MACHINE COMPANY,

' OF ELMIRA, NEW YORK, A CORPORATION OF NEW YORK GENERATOR CONTROL Application filed August 11, 1931. Serial No. 556,366.

This invention relates to an improved generator control for automatic starting mechanism for internal combustion engines and more particularly to means for increasing the effectiveness of generator hold-out devices for automatic starting mechanism.

In automatic starting mechanisms7which rely on current from a generator driven by the engine to be started to prevent actuation of the starting mechanism while the engine is running, it has been found when the engine is adjusted to idle very slowly that if the engine idles unevenly or rolls the generator current in its corresponding fluctuations may drop almost to zero and allow undesired actuation of the starting mechanism.

' It has also been found in practice that an automatic starting mechanism to be commercially acceptable should embody some form of time delay to prevent actuation of the starting mechanism until the engine has come completely to rest, in order to avoid the possibility of engagement of the starting gearing' during a back-rock of the engine flywheel.

It is an object of the present invention to provide a novel device for increasing the effectiveness and utility of a generator holdout for automatic starting mechanism.

; It is another object to provide such a device which renders the hold-out independent of fluctuation in engine speed.

It is a further object to provide such a device which may function as a time delay in conjunction with the generator so as to give the engine time to come completely to rest before allowing actuation of the starting mechanism.

. Further objects and advantages will be apparent to those skilled in this art from the following description taken :in connection with the accompanying drawings in which Fig. 1 is a semi-diagrammatic illustration of one preferred form of my invention;

Fig. 2 is an enlarged detail showing one form of overrunning clutch which may be used in carrying out the invention;

Fig. 3 is a semi-diagrammatic illustration of a second form of automatic starting mech- 50 anism embodying my inv ntion; and

Fig. 4 is a similar view of a third form of automatic starting mechanism embodying the present invention and in which the improved generator hold-out device is relied on to perform the function of a time delay.

Referring first to Fig. 1 of the drawing, there is illustrated an internal combustion engine 10 which is arranged to be started by a starting motor SM energized by a battery 11 under the control of an automatic starting device indicated generally at 12.

The automatic starting device 12 includes a starting switch 13 arranged to be closed by a solenoid 1 1 when the ignition switch 15 is closed, and to be opened by a solenoid 16' which swings the lever 17 downwardly and opens contacts 18 in the circuit of solenoid 14 when the engine starts.

Contacts 18 are held open as long as the engine is running by a generator hold-out coil 19 energized from the generator 21 driven from the engine shaft 22 by any suitable means such as a chain 23, sprocket 24 fixed to the engine shaft and sprocket 25 drivingly connected to the generator shaft 26.

It has been found as above pointed out that in installations of this character in which the generator driving pinion 25 is rigidly mounted on the generator shaft, slow and uneven idling may cause the hold-out coil 19 to become sufliciently deenergized to allow the contacts 18 to close and cause the closure of the starting switch. According to this invention, such undesired closure of the starting switch is avoided by rendering the generator substantially independent of such fluctuations in engine speed. This may be accomplished as illustrated in Figs. 1 and 2 by mounting the sprocket 25 loosely on the generator shaft-26 and connecting it thereto by' means of an overrunning clutch. This clutch may be of any preferred type, one form being illustrated in Fig. 2. As there shown, the generator shaft 26 has keyed thereon a clutch member 27 havingrecesses 28 adapted to receive balls or rollers 29. These rollers are arranged to wedge between cam surfaces 31 on the clutch member and the internal surface 32 of the sprocket 25,and are preferably urged into wedging engagement between said surfaces as by means of spring-pressed thimbles A one-way driving connection is thus provided between the sprocket 25 and the generator shaft 26 which allows the generator shaft to overrun the sprocket by virtue of the momentum of the generator armature and its associated parts.

If deemed desirable, the rotational inertia of the generator shaft and its associated parts may be increased by mounting an inertia elementor flywheel on saidshaft such as inclicated at 34. This flywheel member may or may not be inclosed within the generator casing or a supplemental casing fixed thereto, and may be rigidly mounted on the shaft or connected thereto by any preferred form of yielding or slip connection.

v It will be understood that during slow idling of the engine 10, there is very little load on the generator since its voltage is too low to close the cut-out 35 and the only load is therefore the slight amount of current traversing the voltage coil of the cut-out and the hold-out coil 19. Should the engine rotation then vary or set up the rythmic fluctuations commonly occurring under such circumstances. the generator being retarded principally by brush friction only will overrun the engine during the periods of slower rotation and remain effective to hold out the starting mechanism. Moreover, should the engine stall, the generator will continue to rotate for several revolutions, maintaining the effective ness of the hold-out for a time interval after the stoppage of the engine shaft depending on the inertia of the generator rotor and the friction of the brushes, bearings, etc.

In Fig. 3 of the drawings, there is illustated a similar combination to that illustrated in Fig. 1 but including another form of automatic starting device. In this form of the-invention, the automatic starting device indicated generally at 36 comprises a starting switch 37 adapted to be closed by a solenoid 38, one terminal of which may be connected tothe battery 11 by an ignition switch 39, while the other terminal is grounded at 41' on the generator 21. Initial closure of the ignition switch 39 thus causes closure of the starting switch 37, but rotation of the generator 21 sets up an E. M. F. in opposition'to the battery voltage, thus deenergizing coil 38, allowing the starting switch' to open and causing said switch to remain open as long as the generator is running.

In this embodiment of the invention, the generator 21 'isdriven from the e'ngine 10 through a drive similar to that illustrated in Fig. 1 and including an overrunning clutch 42 of any preferred form. This enables the generator to rotate with comparative steadiness and renders it effective to hold, out the starting mechanism in spite of engine roll in the manner set forth with respect to the structure illustrated in Fig. 1.

In Fig. 4 there is illustrated a third embodiment of the invention including an automatic starting device 43 having a starting switch 44 adapted to be closed by a solenoid 45 similar to solenoid 38 in Fig. 3. The solenoid 45 howeve instead of being grounded on the generator 21, is connected to a centrifugal governor device mounted on the generator 21 and arranged to open the circuit of solenoid 45 responsive to rotation of the generator shaft. The governor includes a ring contact 46 connected to said solenoid and a movable grounded contact 47 normally held in engagementwith'contact 46 by a spring 48 through a linkage system indicated generally at 49 but adapted to be moved out of engagement therewith by means of centrifugal weights 51. In this embodiment also the generator sprocket- 25 is connected to the generator shaft 26 by some form of one-way driving connection indicated at 52 in order to allow the generator rotor to'overrun the engine in the manner set forth in connection with the embodiments previously described.

It will be noted that in Fig. 1 of the drawing there is illustrated a time delay in connection with the automatic starting device 12 in the form of a weight 53 which is adapted to vibrate and prevent effective closure of contacts 18 for a predetermined length of .t

time after withdrawal of lever 17 In the structure illustrated in Fig. 3, a time delay is also shown in the form of a dash-pot 54 for retarding the closure of the starting switch. It will be understood that these time delay elements may be used if deemed desir-' able in conjunction with the present invention, but may be dispensed with as shown in the embodiment illustrated in Fig. 4 where the overrunning action of the generator is solely relied upon to provide the time delay in case of engine stall, before the automatic starting device becomes effective to close the starting switch.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that various other embodiments are possible and various changes may be made in the precise forms and arrangements of the elements shown -\bustion engines,

a starting circuit including a motor and a starting switch, means for clos- ,ing the starting switch, a generator, means controlled by the generator for preventing the operation of the closing means, and means for driving the generator from the engine to be started, said means including a one-way driving connection.

3. In an electrlcal system for internal combustion englnes, a startlng clrcuit lncludlng a motor and a starting switch, means for closing the starting switch, a generator, means controlled by the generator for preventing the operation of the closing means, and means including an overrunning clutch for driving the generator from the engine to be started.

4. In an electrical system for internal combustion engines, a starting circuit including a motor and a starting switch, means for closing the starting switch, a generator,

7 means controlled by the generator for'preventing the operation of the closing means,

a means including a one-way driving connection for driving the generator from the engine to be started and means for increasing the inertia of the generator rotor.

5.;In an electrical system for internal combustion engines, astarting circuit including 1 a motor and a starting switch, means for closing the starting switch, a generator, means controlled by the generator for preventing the operation of the closing means, means including a one-way driving connection for driving the generator from the engine to be started and a flywheel drivingly mounted on r the generator shaft.

In testimony whereof I have signed this specification. I

DANIEL L. WERTZ. 

